Consumer advice site Radical Guide suggests that you view your credit card as a potential earnings opportunity. If you're the kind of consumer who pays off your balance each month, you can take credit to the next step: income. The advice centers around a three-point strategy: rewards (such as rewards, discounts and cash-back policies), free loans (interest-free spending from the day of purchase until the payment due date) and built-in purchase protection. Worth a look if you're shopping for credit.